This is an application to support the Fourth Symposium on Neural Transplantation, to be held in Washington, D.C. on July 12-16, 1992. The previous three meetings stressed many different types of grafts and phenomenological studies documenting survival, growth and function. In this fourth meeting, a number of critical aspects of applied grafting have evolved to the point of meriting a specific focus. These include (1) evaluation of transplant efficacy in animal models of neurodegenerative disease, (2) utilization of neural grafts in clinical disorders, (3) optimization of grafts using neuronotrophic factors, (4) neuroimmunology, and (5) application of recombinant DNA technology to grafting protocols, amongst others. Most importantly, however, this meeting will stress, at the basic science level, the use of implants to understand the fundamental mechanisms associated with maturation, regeneration, and regulation of connectivity in the vertebrate CNS. In addition, emphasis will be placed on modern molecular biological approaches which might allow other types of cells to substitute for fetal neuroblasts as donor material. The specific an longer term objective is to enable different neuroscience disciplines, represented by prominent individuals and those in-training, to interact together to make theoretical and technological advances in models of brain repair. Both oral presentation and poster sessions will be used to disseminate information at the meeting. Arrangements have already been made to publish extended abstracts as a journal supplement and to publish the symposium proceedings as a book. This would insure both timely and detailed dissemination of information to the neuroscience community. In addition, Travel Awards for students and postdoctorals with emphasis on underrepresented minorities will be available.